Samantha Morton as Annie Parker

Helen Hunt as Mary-Claire King

Aaron Paul as Paul

Alice Eve as Louise

Maggie Grace as Sarah

Rashida Jones as Kim

Corey Stoll as Sean

Richard Schiff as Mr. Allen

Bradley Whitford as Marshall

Marley Shelton as Joan

Ben McKenzie as Tom

James Tupper as Steve

Robert Pine as Dr. Frank

Bob Gunton as Dr. Benton

Chris Mulkey as Ralph Parker

Chad Lindberg as Funeral Home Employee

Benjamin Stockham as Young William (Age 8)

Ryan Wynott as Young William (Age 12)

Jade Duncan as Young Annie Parker

Olivia Rose Keegan as Young Joan Parker